The present disclosure relates generally to seismic imaging. More specifically, the present disclosure relates to methods, software, and systems for 3D multiple prediction and removal.
“Noise” is always present in migrated seismic volumes. Some of these noises are due to multiple reflections as seismic waves propagate in the subsurface. These multiple reflections are essentially false images in the subsurface that can often add to the drilling risk for oil and gas exploration if they are wrongly characterized as real events. This is especially true for deep and complex targets such as subsalt, where primary reflections are weak and multiple reflections are strong. As a result, the oil and gas industry has invested significant resources in the processing of seismic data in an effort to remove or attenuate multiples in seismic data.
3D surface related multiple elimination (3DSRME), is a widely accepted method for predicting and removing multiples in seismic data. In general, 3DSRME, requires areal coverage of sources and receivers in 3D space and is computationally expensive. Generally, the 3DSRME method requires seismic traces at zero offset which are often not available for both narrow azimuth and wide azimuth marine seismic data. Current industry practices are to create the zero offset data using very simplified data extrapolation and migration methods. These practices may, however, lead to errors in predicting and removing multiples from input seismic data, sometimes even to the extent that primary reflections are removed while the multiples are left behind.